Drill-sharpener



INVENTOR.

Wi/AM $41 A TTNEY W. A. SMITH.

DRILL SHARPENER.

APPLICATION FILED APR- I. I920.

l E SIT E WILLIAM A. SMITH, OF EASTON, PENNSYLVANIA, ASSIGNOR '10 INGERSOLL-RAND COMPANY, 015 JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY;

DRILL-SHARPENER.

ieaaaoa.

To all whom it may concern:

Beit known that I, WILLIAM A. SMITH, a citizen of the United States, residing at Easton, in the county of Northampton and State of Pennsylvania, have invented a certain new and useful Improvement in Drill- Sharpeners, of which the following is a specification.

This invention relates to drill sharpeners, but more particularly to that type of sharpener in which the drill steel is operated upon by fixed and movable dies, the m ovable die being carried by a reciprocating cross head having a fluid actuated piston or plunger.

In tools of this type the movable parts are heavy and considerable force is necessary in bringing the dies together for the sharpening operations, so that breakage may occur unless provision is made to guard against accidental uncushioned impact of the dies, or too "great impact of the reciprocatin and stationary parts of the machine on elther the up or down stroke.

Means have heretofore been provided for cushioning the parts of a sharpener either on the up stroke or the down stroke, but I have devised simple and efficient means for cushioning the reciprocating member on both the up and down strokes so that ar and breakage is prevented under substantially all circumstances.

I have found that the cushioning device should not come into operation too early on either the upor down stroke of the movable member because this tends to slow up the operation of the machine, which should be positive and quick acting in order toenable the operator to sharpen the maximum number of bits in a given time. Accordingly, an object of this invention 1s to provide cushioning means for both ends of the stroke of the reciprocating member which are positive in operation, but do not slow up the operation of the machine.

A further object of the invention is to secure eflicient' cushioning of the reciprocating rhember and its parts in a sharpener of the type in which constantfiuid pressure is applied and maintained upon the under side or on. the lower end of the shank of the fluid actuated plunger. In such case the cushioning means for the up stroke 1s particularly desirable in addition to the cushioning of the down stroke.

The invention is illustrated in one of itsupon which is Specification of Letters Patent. Pate t d Umh; 11% 1192 1 1 Application filed April 1, 1920. Serial No. 37,M3. v

member or die receiving socket G. The sta- I tionary half of the die receiving socket H formlng the stationary die member is preferably formed on the anvil block J.

The plunger rod E shown in the drawing,

is formed with a stem K provided with the sleeve L forming a shank or extension for the piston D adapted to reciprocate within the reduced cylinder extension 0 suitably supported within the base A.

.The admission and distribution of motive fluid pressure to the cylinder C for actuatmg the piston D is controlled by a suitable valve P conveniently mounted in the valve chest Q at the side of the machine. The valve may be operated by a suitable handle and through the medium of a rack R at one end of the valve. 7

In the type of machine illustrated in the drawings, motive fluid pressure is constantly supplied to the end face of the piston shank or extension K and its surroundin sleeve L through the passage S and inlet 'lFso that the piston D and cross head F carrying the die member G is constantly urged in an upward direction.

Motive fluid for actuating the piston D is admitted at the inlet port U of the valve chest and may pass from said inlet port through the passage V above the piston D for the down stroke. The valve is shown in the drawing in exhaust position, closing the inlet to the cylinder. On the up stroke, pressure is exhausted from the cylinder through the valve chest to the exhaust port 'W. The underside of the piston D is open upper portion of the case A is provided with a projection Z adapted to enter the recess or pocket Y and trap a small amount of air between the piston-and the projection head is provided with the recess or pocket a and the upper surface of the piston D is provided with a projecting portion 12 adapted to enter the recess or pocket a and trap a small amount 02f air for cushioning purposes.

"I have found that in accordance with this construction, the speed of the piston D may be increased without danger of breakin the operative parts of the machine, and am. enabled to cushion the reciprocating parts both on the up stroke and the down stroke 1 without material loss of power, which oopocket at the upper end'of the cylinder adapted to receive a projecting portion on the piston for cushioning the piston on the up stroke, ports through the lower wall of the cylinder affording communication between the interior of the cylinder and the atmosphere, and means forming part of the piston for closing communication through said ports when the piston approaches the end of its down stroke, whereby air is trapped below the piston to form a cushion. 2. A drill sharpener havin a stationary die member, a reciprocating ie member, a cylinder, a piston therein connected to operate the reciprocating die member, fluid actuating means !for said piston, ports through the lower wall of the cylinder affording communication between the interior ofthe cylinder and the atmosphere, and means forming part of the piston for closing communication through said ports when the piston approaches the end of its down stroke, whereby air is trapped below the piston to form a cushion.

' In testimony whereof, I have hereunto set In hand.

y WILLIAM A. SMITH. 

